Three explosions rock Riyadh

At least two people have been killed and up to a hundred injured a bomb attack on a residential compound in the Saudi capital Riyadh.

Three explosions, at midnight local time, came after gunmen broke into the upmarket compound of about 200 villas and exchanged fire with security guards, a Saudi government official said.

An Interior Ministry official said the attack was by a suicide car bomber. He said 86 people were wounded and two killed, both security guards.

However, immediately after the explosion, there were widely conflicting reports of the number of dead.

An official at a Riyadh hospital said dozens of people were killed, but that apparently was wrong.

Diplomats and officials said most of the residents of the compound's 200 villas were Lebanese.

Some Saudis also live there, plus a few German, French and Italian families.

Officials at the King Khaled Specialist Hospital and the King Faisal Special Hospital and Research Centre said the two hospitals received 38 wounded people.

Flames could be seen still burning at the compound several hours after the explosion.

State-run Saudi TV aired live footage from the devastated section of the residential compound, showing collapsed buildings, piles of rubble, twisted metal and debris spread over a large area.

A woman living in the compound said in a telephone interview that "there is lot of blood" at the scene of the explosions.

"I am extremely terrified - I am really scared. I felt it was an earthquake," the woman said.

The attack comes a day after the US is closed its embassy in the Saudi Arabian capital Riyadh, citing 'credible' terror threats.